Friday, February 17, 2017

Beijing Orders Closure Of Live Bird Markets To Control H7N9

#12,337

The link between live poultry markets and the transmission of H7N9 to humans has been long established. In the summer of 2014, in CDC: Risk Factors Involved With H7N9 Infection
we looked at a case-control study conducted by an international group
of scientists, including researchers from both the Chinese and the US CDC which concluded.

Exposures
to poultry in markets were associated with A(H7N9) virus infection,
even without poultry contact. China should consider permanently closing live poultry markets or aggressively pursuing control measures to prevent spread of this emerging pathogen.

Closure of LPMs reduced the mean daily number of infections by 99%
(95% credibility interval 93—100%) in Shanghai, by 99% (92—100%) in
Hangzhou, by 97% (68—100%) in Huzhou, and by 97% (81—100%) in Nanjing.
Because LPMs were the predominant source of exposure to avian influenza A
H7N9 virus for confirmed cases in these cities, we estimated that the
mean incubation period was 3·3 days (1·4—5·7).

Interpretation

LPM closures were effective in the control of human risk of avian influenza A H7N9 virus infection in the spring of 2013. In the short term, LPM closure should be rapidly implemented in areas where the virus is identified in live poultry or people. In the long term, evidence-based discussions and deliberations about the role of market rest days and central slaughtering of all live poultry should be renewed.

While the transmission of H7N9 (or H5N6, H5N1, H10N8, etc.) to humans is the most obvious threat from live bird markets, they also likely play a major role in the evolution (and creation) of novel flu viruses.

Despite
the evidence that it would greatly reduce the transmission of the
virus, closing LMBs (Live Bird Markets) has been a tough sell to the Chinese public. Purchasing
live market birds is deeply ingrained in their culture, as it reassures
the buyer that the bird is both fresh and healthy.

A plan that, despite its good intentions, obviously never went anywhere.

Still, in years past - when H7N9 cases have been far fewer than during this 5th epidemic wave - hard hit provinces have shut down their live bird or poultry markets. Often for weeks, and almost always showing an immediate decline in human infections, despite ongoing black market sales of birds.

This year - for reasons that are difficult to fathom - market closures appear to have been far more sporadic, slower to be ordered, and have often only been for a few days duration.

Overnight, however, there are reports that Beijing may be ordering a harder stance.

A Xinhua report this morning, published by the Shanghai Daily, details the plans to close LBMs in regions where H7N9 cases have been reported.

Source: Xinhua |
February 17, 2017, Friday(EXCERPT)The situation has prompted health authorities to step up prevention
and control measures. The National Health and Family Planning Commission
is training workers in screening and early diagnosis, and in treatment
of critically ill patients. The commission has also ordered a ban on the
live poultry trade in places where H7N9 cases have been reported.

On Thursday, Guangzhou, capital of south China's Guangdong Province,
stopped live poultry trading for the rest of the month, with all poultry
markets to be thoroughly disinfected.

Exposure to live poultry is the major source of infections,
particularly in rural areas. All human infections in Guangdong
originated in live poultry and February - March is a crucial time for
epidemic control, according to the local health commission.

Zhejiang, with 35 human infections and 11 fatalities in January, is
suffering the worst epidemic in three years. The virus was found in 40
percent of live poultry markets this month, compared with 10 percent in
September. All rural live poultry markets there were closed from
Saturday. The trade has been banned in the cities since 2014.

Live poultry sales have also been suspended in Xiamen, Suzhou and several cities in Hunan and Sichuan provinces.

The bans have greatly reduced the number of new infections in many
regions, said Ni Daxin, deputy director of the emergency response center
at the Center for Disease Control and Prevention. Ni suggested
replacing live poultry with frozen birds to reduce the risk of
infection.

Popular or not - moving away from live bird markets is probably the only way for China to get a handle on their yearly H7N9 epidemic. Whether they have the political will this time to see it through, remains to be seen.